The proposed research entails an agenda of studies that focus on social context, family process, and child and adolescent well- being. Kathleen Mullan Harris will serve as a Principal Investigator of the NICHD Family and Child Well-Being Research Network, bringing her knowledge and expertise on a new secondary data source on adolescent health and health behavior as a Co-PI and Associate Director of the National Longitudinal Study of Adolescent Health (Add Health). Harris will study the impact of family and environmental influences on adolescent health, focusing on a particular family context in one individual project (immigrant families) and on a particular health risk behavior in a second individual project (nonmarital pregnancy and childbearing), and will lead a team of interdisciplinary UNC researchers to foster cooperative network activities and research on the interrelationships between family, biological, and environmental influences on children's health and development. Collaborating with Harris on the proposed research projects are Guang Guo, a colleague in the Sociology Department and on-going collaborator on research on children in poverty; Desmond K. Runyan, a pediatrician and epidemiologist in the School of Medicine at UNC and a Network PI during its first cycle; Martha J. Cox, a developmental psychologist at the Frank Porter Graham Child Development Center at UNC and a PI in the NICHD Early Child Care Research Network; and Johanne Boisjoly, a sociologist at the University of Quebec at Rimouski and collaborator with Harris on numerous Add Health projects. Two individual research projects are proposed. The first examines the health status and health behavior of children in immigrant families and explores the mediating role of contextual influences on immigrant health and well-being, including family, peer, school, and neighborhood effects. The second project examines a comprehensive set of causes that are related to nonmarital pregnancy and childbearing in the U.S., including the effects of social context, relationship experiences, and welfare policies. Three cooperative research projects are proposed. The first examines the effects of welfare reform policies on child well-being using multiple datasets across various developmental stages of children. The second project focuses on family process and the impact of father involvement on child well-being within the context of family structure, family income, and race and ethnicity. The third project assesses the role for biological factors typically ignored in most social science research on family and child well-being.